Automobile parts, such as interior materials for passenger vehicles, may be produced by various molding processes, such as slush molding. For example, dash board coverings, as well as covering for other interior vehicle features may be produced by slush mold processing. The slush molding processes may utilize molds which are complementary shaped relative to the molded part to form a desired geometry. However, there is a need for improved methods for determining proper timing for replacing molds utilizing in vehicle part manufacturing.